A variety of products include hydrocarbon-based materials in them e.g., aliphatic hydrocarbons. For example, Raid, which is a trademarked product of SC Johnson, includes an aliphatic hydrocarbon solvent, which is sold by ESSO Imperial Oil of Toronto, Ontario, Canada, under the product designation EXXSOL D95 Solvent.
The use of hydrocarbon-based materials as a component in products to be dispensed from a container has created problems in the labeling of such containers. Specifically, prior art polyolefin-type label structures, such as polypropylene or polyethylene, are susceptible to swelling from contact with aliphatic hydrocarbons, causing the labels to wrinkle, shrink and otherwise distort (e.g., become wavy).
It is extremely difficult to avoid exposing labels to hydrocarbon-based materials, e.g., materials including aliphatic hydrocarbons in them, during the assembly and testing of containers including products with such hydrocarbon-based materials in them. Specifically, after a container is filled with the product to be dispensed, and before applying the label, a dispensing nozzle commonly is inserted into the container. During this insertion operation it is quite common for some of the product, which includes hydrocarbon-based materials therein, to leak onto the outer surface of the container. Even when dried, over time the residual hydrocarbon-based material on the surface can adversely affect the quality of a subsequently applied label. Moreover, before labeling the container it is common practice to direct the container through a water bath to test for leaks. During this process, residual hydrocarbon-based materials on the container surface can contaminate the test water. Moreover, if a leak does exist in the container being tested, the test water is further contaminated by the leaking material. Thus, the test water itself ultimately becomes contaminated with hydrocarbon-based material and that material actually is transferred to the surface of containers being tested therein. Thus, a serious problem has existed in employing plastic labels on containers including hydrocarbon-based materials therein, causing the industry to use more expensive product identification systems, such as lithographic printing of product identification information directly on the outer surface of the product dispensers. In fact, lithographic printing has remained the preferred method of product identification for products containing a hydrocarbon-based material therein.
Based on the present state of the art a need exists for less expensive product labeling systems, and in particular, for solvent resistant labels that are resistant to hydrocarbon-based materials to thereby permit such labels to retain their integrity without distorting (e.g., without wrinkling, shrinking, or delaminating) in the event they come into contact with such hydrocarbon-based materials employed in numerous packaged products. It is to such solvent-resistant labels and the combination of containers including such labels that the present invention relates.